1. Field of the Invention
This invention relates to a radar sensor system installed in a vehicle and a radar sensor installed in a vehicle and in particular to a vehicle-installed radar sensor system and a vehicle-installed radar sensor in which a transmission section and a reception section are provided separately.
2. Description of the Related Art
A radar sensor using a millimeter wave, a submillimeter wave, etc., is used for monitor ahead of a vehicle for the purpose of preventing a collision of a vehicle and an operation trigger of a person protection function at the vehicle collision time. (For example, refer to JP-A-2001-201557) In a vehicle with a bumper of the vehicle as a permeable member, the radar sensor can also be disposed in a closed space formed between the bumper and the vehicle body from the viewpoint of the design.
To detect a target at a short distance, a transmission section for transmitting a radar wave and a reception section for receiving a reflected wave on the target need to be provided separately. In this case, it is important to prevent the reception section from directly receiving the transmission wave from the transmission section. (For example, refer to JP-A-Hei. 6-174829)